Fluid Simulator: odd behaviour. Cache problem?
Data for fluid sims is saved to external files, if the current blend is not saved this will be in a temporary folder, it may also get a temporary path if the domain is created before saving the blend file, even if the simulation isn't baked before saving. While this should use a random path name generated each time blender is run, there is a chance of old temporary data being used, thinking it is the current sim data.

The path used for saving sim data can be found in the domain settings. You can change the path to prevent the old data being seen.



While other simulations provide options to clear the baked data, the current fluid sim does not.